Light Source Modules for Coherent Noise Mitigation
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Solution Overview
Problem
Coherent noise in optical measurement systems degrades spectroscopic information by causing graininess and intensity patterns in measured signals, making it difficult to determine accurate spectroscopic data.
Innovation Solution
The use of multiple light sources in a light source module that provide de-cohered light through phase shifts and different wavelengths, combined into a single output to mitigate coherent noise, while also offering redundancy and increased power for noise reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single light source is used, then the system is simple and reliable, but coherent noise degrades spectroscopic information quality
Solution Approach 1:
The patent divides the light source into multiple independent light sources (e.g., multiple LEDs or lasers) that each emit at different wavelengths. This segmentation allows the system to transmit multiple wavelengths simultaneously through the sample, enabling coherent noise mitigation while maintaining measurement precision through the combined spectral information.
Solution Approach 2:
The patent combines the outputs of multiple light sources to create a composite light beam that contains multiple wavelengths. This merging approach allows the system to achieve both simplicity (as a single combined beam is used) and improved measurement precision (through the multi-wavelength composition that mitigates coherent noise).
2Measurement precision
If multiple light sources at different wavelengths are used, then coherent noise is mitigated, but the device complexity increases
Solution Approach 1:
The patent designs the system so that multiple light sources serve multiple functions: they provide both the illumination needed for spectroscopic measurement and the noise mitigation through their different wavelengths. This multi-functionality reduces the need for separate components, thereby managing device complexity while achieving coherent noise mitigation.
Solution Approach 2:
The patent utilizes parameter changes in the light sources, specifically varying wavelengths while maintaining similar spectral shapes. This parameter variation enables coherent noise mitigation through the interstitial range concept, where the wavelength separation is greater than the coherent noise bandwidth but less than the spectroscopic information bandwidth, achieving noise reduction without excessive complexity.
3Loss of information
If multiple wavelengths are combined, then spectroscopic information can be obtained, but coherent noise patterns appear in the signal
Solution Approach 1:
The patent converts the harmful coherent noise patterns into beneficial noise mitigation by strategically selecting wavelength separations. The coherent noise at different wavelengths is uncorrelated, allowing the system to use the noise from one wavelength to mitigate the noise in another, thereby converting the harmful noise into a useful noise reduction mechanism.
Solution Approach 2:
The patent employs periodic action through the systematic variation of wavelengths across the spectrum. By spacing wavelengths at regular intervals within the interstitial range, the system creates a periodic spectral structure that enables consistent noise mitigation across all measurement wavelengths, transforming the noise problem into a manageable periodic pattern that can be addressed systematically.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively reduces coherent noise, allowing for more accurate spectroscopic measurements by treating multiple wavelengths as spectroscopically equivalent while providing different coherent noise views, thereby improving signal quality.
Implementation Method 1
a first semiconductor light source operative to emit a first wavelength of light and a second semiconductor light source operative to emit a second wavelength of light
Implementation Method 2
combining the first light output and the second light output into a combined light output having the first wavelength and the second wavelength
Data Source
AI summary
Configurations for light source modules and methods for mitigating coherent noise are disclosed. The light source modules may include multiple light source sets, each of which may include multiple light sources. The light emitted by the light sources may be different wavelengths or the same wavelength depending on whether the light source module is providing redundancy of light sources, increased power, coherent noise mitigation, and/or detector mitigation. In some examples, the light source may emit light to a coupler or a multiplexer, which may then be transmitted to one or more multiplexers. In some examples, the light source modules provide one light output and in other examples, the light source modules provide two light outputs. The light source modules may provide light with approximately zero loss and the wavelengths of light may be close enough to spectroscopically equivalent respect to a sample and far enough apart to provide coherent noise mitigation.